<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./vue.js"></script>
    <style>
        #wrap{
            display: flex;
            flex-wrap: nowrap;
        }
        #wrap>div:first-of-type>img{
            width: 100%;
        }
        #wrap>div:last-of-type>img{
            width: 0px;
        }
    </style>
</head>
<body>
    <div id="app">
        <div id="wrap"  :mouseover="width='800px'" >
            <div>
                <img src="./img/mini.png" alt="">
            </div>
            <div>
                <img src="./img/big.jpg" alt="">
            </div>
        </div>
    </div>
    <script>
        new Vue({
            el:"#app",
            data:{
                width:'800px'
            }
        })
    </script>
</body>
</html>